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Soll DR. White-opaque switching in Candida albicans: cell biology, regulation, and function. Microbiol Mol Biol Rev 2024; 88:e0004322. [PMID: 38546228 DOI: 10.1128/mmbr.00043-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024] Open
Abstract
SUMMARYCandida albicans remains a major fungal pathogen colonizing humans and opportunistically invading tissue when conditions are predisposing. Part of the success of C. albicans was attributed to its capacity to form hyphae that facilitate tissue invasion. However, in 1987, a second developmental program was discovered, the "white-opaque transition," a high-frequency reversible switching system that impacted most aspects of the physiology, cell architecture, virulence, and gene expression of C. albicans. For the 15 years following the discovery of white-opaque switching, its role in the biology of C. albicans remained elusive. Then in 2002, it was discovered that in order to mate, C. albicans had to switch from white to opaque, a unique step in a yeast mating program. In 2006, three laboratories simultaneously identified a putative master switch gene, which led to a major quest to elucidate the underlying mechanisms that regulate white-opaque switching. Here, the evolving discoveries related to this complicated phenotypic transition are reviewed in a quasi-chronological order not only to provide a historical perspective but also to highlight several unique characteristics of white-opaque switching, which are fascinating and may be important to the life history and virulence of this persistent pathogen. Many of these characteristics have not been fully investigated, in many cases, leaving intriguing questions unresolved. Some of these include the function of unique channeled pimples on the opaque cell wall, the capacity to form opaque cells in the absence of the master switch gene WOR1, the formation of separate "pathogenic" and "sexual" biofilms, and the possibility that a significant portion of natural strains colonizing the lower gastrointestinal tract may be in the opaque phase. This review addresses many of these characteristics with the intent of engendering interest in resolving questions that remain unanswered.
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Affiliation(s)
- David R Soll
- Department of Biology, University of Iowa, Iowa City, Iowa, USA
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Wangsanut T, Arnold SJY, Jilani SZ, Marzec S, Monsour RC, Rolfes RJ. Grf10 regulates the response to copper, iron, and phosphate in Candida albicans. G3 (BETHESDA, MD.) 2023; 13:jkad070. [PMID: 36966423 PMCID: PMC10234403 DOI: 10.1093/g3journal/jkad070] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 01/19/2023] [Accepted: 02/27/2023] [Indexed: 03/27/2023]
Abstract
The pathogenic yeast, Candida albicans, and other microbes must be able to handle drastic changes in nutrient availability within the human host. Copper, iron, and phosphate are essential micronutrients for microbes that are sequestered by the human host as nutritional immunity; yet high copper levels are employed by macrophages to induce toxic oxidative stress. Grf10 is a transcription factor important for regulating genes involved in morphogenesis (filamentation, chlamydospore formation) and metabolism (adenylate biosynthesis, 1-carbon metabolism). The grf10Δ mutant exhibited resistance to excess copper in a gene dosage-dependent manner but grew the same as the wild type in response to other metals (calcium, cobalt, iron, manganese, and zinc). Point mutations in the conserved residues D302 and E305, within a protein interaction region, conferred resistance to high copper and induced hyphal formation similar to strains with the null allele. The grf10Δ mutant misregulated genes involved with copper, iron, and phosphate uptake in YPD medium and mounted a normal transcriptional response to high copper. The mutant accumulated lower levels of magnesium and phosphorus, suggesting that copper resistance is linked to phosphate metabolism. Our results highlight new roles for Grf10 in copper and phosphate homeostasis in C. albicans and underscore the fundamental role of Grf10 in connecting these with cell survival.
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Affiliation(s)
- Tanaporn Wangsanut
- Department of Biology, Georgetown University, Washington, DC 20057, USA
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Sylvia J Y Arnold
- Department of Biology, Georgetown University, Washington, DC 20057, USA
| | - Safia Z Jilani
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA
- Center for Sustainable Nanotechnology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sarah Marzec
- Department of Biology, Georgetown University, Washington, DC 20057, USA
| | - Robert C Monsour
- Department of Biology, Georgetown University, Washington, DC 20057, USA
- Morsani College of Medicine, University of South Florida, Tampa, FL 33602, USA
| | - Ronda J Rolfes
- Department of Biology, Georgetown University, Washington, DC 20057, USA
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Conte M, Eletto D, Pannetta M, Petrone AM, Monti MC, Cassiano C, Giurato G, Rizzo F, Tessarz P, Petrella A, Tosco A, Porta A. Effects of Hst3p inhibition in Candida albicans: a genome-wide H3K56 acetylation analysis. Front Cell Infect Microbiol 2022; 12:1031814. [PMID: 36389164 PMCID: PMC9647175 DOI: 10.3389/fcimb.2022.1031814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/10/2022] [Indexed: 11/30/2022] Open
Abstract
Candida spp. represent the third most frequent worldwide cause of infection in Intensive Care Units with a mortality rate of almost 40%. The classes of antifungals currently available include azoles, polyenes, echinocandins, pyrimidine derivatives, and allylamines. However, the therapeutical options for the treatment of candidiasis are drastically reduced by the increasing antifungal resistance. The growing need for a more targeted antifungal therapy is limited by the concern of finding molecules that specifically recognize the microbial cell without damaging the host. Epigenetic writers and erasers have emerged as promising targets in different contexts, including the treatment of fungal infections. In C. albicans, Hst3p, a sirtuin that deacetylates H3K56ac, represents an attractive antifungal target as it is essential for the fungus viability and virulence. Although the relevance of such epigenetic regulator is documented for the development of new antifungal therapies, the molecular mechanism behind Hst3p-mediated epigenetic regulation remains unrevealed. Here, we provide the first genome-wide profiling of H3K56ac in C. albicans resulting in H3K56ac enriched regions associated with Candida sp. pathogenicity. Upon Hst3p inhibition, 447 regions gain H3K56ac. Importantly, these genomic areas contain genes encoding for adhesin proteins, degradative enzymes, and white-opaque switching. Moreover, our RNA-seq analysis revealed 1330 upregulated and 1081 downregulated transcripts upon Hst3p inhibition, and among them, we identified 87 genes whose transcriptional increase well correlates with the enrichment of H3K56 acetylation on their promoters, including some well-known regulators of phenotypic switching and virulence. Based on our evidence, Hst3p is an appealing target for the development of new potential antifungal drugs.
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Affiliation(s)
- Marisa Conte
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
- Ph.D. Program in Drug Discovery and Development, University of Salerno, Fisciano, Salerno, Italy
| | - Daniela Eletto
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
| | - Martina Pannetta
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
- Ph.D. Program in Drug Discovery and Development, University of Salerno, Fisciano, Salerno, Italy
| | - Anna M. Petrone
- Ph.D. Program in Drug Discovery and Development, University of Salerno, Fisciano, Salerno, Italy
| | - Maria C. Monti
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
| | - Chiara Cassiano
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
- Department of Pharmacy, University of Naples ‘Federico II’, Naples, Italy
| | - Giorgio Giurato
- Laboratory of Molecular Medicine and Genomics, Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, Baronissi, Salerno, Italy
| | - Francesca Rizzo
- Laboratory of Molecular Medicine and Genomics, Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, Baronissi, Salerno, Italy
| | - Peter Tessarz
- Max Planck Research Group “Chromatin and Ageing”, Max Planck Institute for Biology of Ageing, Cologne, Germany
- Cologne Excellence Cluster on Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | | | - Alessandra Tosco
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
- *Correspondence: Amalia Porta, ; Alessandra Tosco,
| | - Amalia Porta
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
- *Correspondence: Amalia Porta, ; Alessandra Tosco,
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Iracane E, Vega-Estévez S, Buscaino A. On and Off: Epigenetic Regulation of C. albicans Morphological Switches. Pathogens 2021; 10:pathogens10111463. [PMID: 34832617 PMCID: PMC8619191 DOI: 10.3390/pathogens10111463] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/03/2021] [Accepted: 11/05/2021] [Indexed: 01/08/2023] Open
Abstract
The human fungal pathogen Candida albicans is a dimorphic opportunistic pathogen that colonises most of the human population without creating any harm. However, this fungus can also cause life-threatening infections in immunocompromised individuals. The ability to successfully colonise different host niches is critical for establishing infections and pathogenesis. C. albicans can live and divide in various morphological forms critical for its survival in the host. Indeed, C. albicans can grow as both yeast and hyphae and can form biofilms containing hyphae. The transcriptional regulatory network governing the switching between these different forms is complex but well understood. In contrast, non-DNA based epigenetic modulation is emerging as a crucial but still poorly studied regulatory mechanism of morphological transition. This review explores our current understanding of chromatin-mediated epigenetic regulation of the yeast to hyphae switch and biofilm formation. We highlight how modification of chromatin structure and non-coding RNAs contribute to these morphological transitions.
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